Automatic sheet stacker



June 3, 1930. E; L. DONNELLY AUTOMATIC SHEET STACKER Filed Oct. 5l, 19284 Sheets-Sheet Inventor Z732 0.5 L. Fofana/Zi 'By @m /lttornqy Junel3,1930. l E. L. DQNNELLY 1,761,881

AUTOMATIC SHEET STACKER Filed Oou. 31, 1928 4 Sheets-Sheet 2 InventorZaaslx//zhel@ Ahorn@ June 3. 1930.y

` E. L. DONNELLY AUTOMATIC SHEET ,STACK'ER 4 Filed'ocr. 51, 192e 4sheetssheet 5v June 3, 1930."

E. L. DONNELLY 1,761,881

AUTOMATIC SHEET STACKER Filed Oct. 51, 1928 4 Sheets-Sheet 4 lasvliateritetl June 3, 1930 UNITE-D STATES PATENT oFjFlcE "ENOS L.-,DONNELLY, OF HUNTINGTON, 'WESTVIRGINIA AU'roMA'rro sHra'r s'rAcKERApplication filed October 311928. SerialNm 316,247.

The present invention relates to automatic sheet stackers Adesigned'particularly for 'use in the sheet 'metal industry where sheets ofmaterial are to be moved from one stack to 5 another, or in feedingsheets from a stack to the rolling mill or the like and removing thesheets from the mill and stacking the same. j

One of the important objects of the invenflo tion is to provide anapparatus of this'character embodying ymeans for engaging the uppermostsheet. of the stack and lifting,

swinging'and lowering the same while maintained in a horizontalposition, the lposition of the sheet when lowered, being parallel to itsoriginal position, the mechanism provided j for accomplishing suchmovement of the sheet being automatic in its operation. l

A further important object of the inven- 29 tion is to provideL a set ofvacuum cup sheet metal gripping-members adapted upon engagement with thesheet for lifting and moving' the same together with means 'forautomatically releasingithe sheet upon a predetermined movement oftheapparatus.

. Another important object is to provide a stacker armf mounted forvertical and hori-` zontal swinging movement and providing said arm andsaid control means for the` vacuum cup with an automatic adjustingapparatus whereby to .automatically .adjust the extent of verticalmovement of the arm' as well as the interval between each releasingaction of the cup'in accordance with the increase or decrease of thestack of sheet material.' i v A further important objectoftheinvention'is to provide an apparatus of this character arranged foroperation by fluldpressure.

Other objects and advantages reside in the special construction,combination and arrangement of lthe various elements forming theinvention 'as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings formlng 'part hereof, whereinvlike numerals refer to like 4parts throughout, and in which:

' Figure 1 is a view in side elevation of the .a linee-4 of Figure 3,

Figure 5 is a vertical sectional view through one of the vacuum cups,

Figure 6 is a sectional view through the stacker arm showing thegearprovided for retaining the sheet in parallel position during swinging ofthe arm,

igure 7 is aA fragmentary detail of one vof the hangers for the vacuumcup,

Figure 8 is al transverse sectional view through one of the controlvalves, taken substantially along a line 8 8, of Figure 2,

Figure 9 is a longitudinal sectional view through the valve, taken alonga line 99 of Figure 8, Figure 10 is a' detail of the pivoted armactuating one of the valves through the ver-y ltical movement o'f thestacker arm,

' .Figure 11 is a detail of the pawl and ratchet mechanism for thevertical adjusting screw -vforv controlling'the extent of verticalmovement of the stack'er arm,

Figure l2 is a fragmentary elevational view, with parts broken away andshown in section, of the verticalv adjusting screw and j pivoted valvecontrollever carried thereby,

Figure 13 is a detail of the stop member associated with the-vacuum cuprelease controlmechanism,

Figure 14 is a detail of the control member associated with the vacuumcup release mechanism,v

Figure 15 is a; plan view of the automatic adjusting mechanism for thevacuum cup re-' lease means,

'Figure 16 -is a sectional View through one of the'socket .wheelsthereof, taken along a linel-l'of Figure 15, and

Figure '17 is a vertical sectional view through the automatic adjustingmechanism `frame 10.

The apparatus in its present embodiment includes a frame 5 within whichis `journalled a vertically disposed shaft 6 having a bore of squareshape in cross section extending therethrough and within which isslidably mount-l ved a square shaped standard 7. To the upper end of thestandard 7 is attacheda tubular horizontal arm 8 to the outer end ofwhich is attached a .clamping member 9 roviding means for suspending' asubst-antlally rec-` tangular -shaped vacuum cup supporting The frame 10is horizontally disposed as clearly illustrated in Figui-e1 of thedrawings and is provided with a plurality of rock shafts 11 extendingtransversely of the frame upon each ofwhich is secured a plurality oflaterally extending arms 12 with cables 13 at. tached at their outerends andk secured to vacuum cup releasing .levers 1'4 arranged adjacentthe edges of a series of vacuum cups 15, of a construction well known,in the art,

' said cups being suspended from the frame 10 byvertical rod 16.A ByAforcing the center of the cups downwardlyby thedownward movement of theframe 10, the cups will be fiat-tened out upon the surface of the sheetof material. Accordingly by releasing the cables 13 of any upward pulland allowing the cups to returnto their normal position up'on y theupward movement of the frame, a vac uum Will be created at the underside of the cup causing the edges thereofv to grip the material forlifting the same. The releasing ofthe cup will be accomplished byraising the frame 10 while retaining t-he -cup in a flattened conditionby the proper manipulation of the cable 13.

Thev vacuum cup' 15 may be adjusted verti- I cally with respect to theframe by means Vof socket 17 carried by the frame and through which theupper ends of the r'od 16 are slid ably inserted and retained inposition therein by set screws 18. l l

The rock shafts 11 are connected for uniform movement by alongitudinally'extending tie rod 19 connected to the shafts throughlevers 20, said tie rod lbeing provided with an upwardly extending arm21 tothe upper end of which is secured theouter end of a v stem 22inserted through one end of a cylinder 23 carried by the frame, and withits inner endattached to a kpiston-'24 operatively arranged within saidcylinder.

yThe piston 24 is operated byfa Huid pressure, preferably compressedair,' admitted into the opposite end to the cylinder 23 through air hose26 extending through the tubular arm 8 and extending to a control.

valve 27. This control valve is of a two-way construction sol as toalternately admit air into the opposite end of the cylinderforreciprocally actuating the piston.

Upon the movement of the piston in one direction the tie rod 19 isactuated so as to partially rotate each of the rock shafts l1 andthrough their connection with the vacuvum cup releasing levers 14tobreak the vacuum and permit disengagement of. the cup from the sheetof material, indicated at 28 y in Figure 1 of the drawings. The movementof the piston in the opposite direction permits a return of the cups totheir normal position `for gripping the sheet of material and hoist thesame upon the vertical movement of the standard 7 in amanner to bepresently ex-k i plained.

.In order that the sheet may be moved from one position to another, inparallel relation,

the .upper portion Vof the frame 10 is pro-` vided with'a'bevel gear 29rotatably mounted on a hanger 30vdependin from the/ clamp 9 and fromwhich gear the rame 10is suspended. T he bevel gear 29l is operatedthrough a pinion gear 31 attached-'to a shaft 32 jourvnaled in bearingbrackets 33 carried-by the arm, Asaid shatbeing disposed parallel'thereto.

v vThe innerend of the shaft 32 is connected to Y:'Vvertically disposedtelescoping shaft section 34 through a universal coupling 35, the

lower portion ofthe telescoping shaft section indicated at' 36 beingjournaled in the frame 5 andis provided at its lower end with a piniongear 37 operabley through a gear 38 formed on the shaft 6. 4 y

The upper menber of the telescoping shaft section '34 is slidablydisposedin a guide bracket 39. It will beapparent from the foregoingVthatv the rotary-movement of vthe Shaft'6 for swinging the arm 8 will betransmitted'to the' frame 10 sfo. as to rotate the framein a directionopposite from the swinging movement of the arm and thus maintain thesame in parallel relation with respect to l the sheets of material to bestacked. At the same time the telescoping sections ofthe shaft`permitsvthe gears to be maintained in con-v stant engagement during the.vertical movement of the arm; o

' The lower end of the standard 7 is attached `to the outer end ofavertically disposed pis-l ton rod 40 extending through one end of acylinder 41 and havlng a piston 42 attached at its lower end andoperatively arranged inv said cylinder. Air hose' or pipes 43 and 44 areconnected respectively at the upper and lower ends of the cylinderandextend to a4 control valve 45 togwhich a feedpipe 46 is attached andconnected with a suitable supply of air under pressure (not shown).

This control Valve 45. like the control valve 21, 1s adapted toalternately feed air into the opposite end ofthe cylinderforreciprocally actuating the piston 42 and thus raise and lower theframe 10 through the standard and. arm 7 and 8 respectively.

i An `arm 47 extends radially from one sideV horizontally'disposed, asclearly illustrated in Figures l and 2 of the drawings and is alsoconnected at its opposite ends with air hose 53 and 54 communicatingwith a control valve lThis control valve 55 is likewise adapted toalternately admit compressed air into the opposite ends of the cylinder49 for reciprocally actuating the piston 50 therein and thus to rock theshaft 6 through the connection of the piston with thearm 47. In thismanner provision is made for the forward and backward Aswinging of thearm 8 in a horizontal plane.

The construction' of the control valves 27,

45 and 55 is illustrated in detail in Figures Each of the valves 8 and 9of the drawings. include a cylindrical casing 56 having a connection 57at one end for attaching a feed pipe extending to a suitable source ofair under pressure. y

A rotor 58 is operatively mounted within the'casing having a vstem 59extending outwardly through thecover plate 60 of the casing disposed atthe end thereof opposite fromf the connection 57..l y

The end of the rotor adj acent the air intake connection 57,'isvformedwith a central bore 6 1 communicating with said connection, saidlbore 'terminating Within the rotor ina" pairof. oppositely1 extendingair passages 62.

' The air passages 62 extendlaterally through the walls' of the rotor4and are adapted to communicate selectively with connections 63 and 64formed inthe walls of the casing at angles of ninety degrees withrespect to each other andto .which the air hose leading to the oppo-4site ends of the vvvcylinders are 'respectively attached. l

At diametrica'lly opposite sidesof the rotor 158 is a pair oflongitudinally extending grooves 65 terminating atvone end in avcircumferentially extending groove66; each of said vrcmuferentialgrooves extending only-part way about the surface of the rotor. Anexhaust port 67 is formed in the casing 56 in a position forcommunicating with the respective grooves 66 upon a predeterminedpositioningof the rotorand when either of the grooves 65 are in aposition for communication with either of the connections 63 or 64.

As will he clearly observed from an inspection-of Figure 8 of thedrawings, the grooves 65 are arranged in position upon the rotor atangles of ninety degrees with respect tc the vlateral passages 62 sothat when one of thc lateral passages is' in communication with one ofthe connections 63 or 64, one of the grooves 65 will be in communicationwith the other of said connections.

Thus when one air hose of the respective cylinders is in communicationwith the feed pipe connection 57, the other air hose is in communicationwith the exhaust or discharge port 67so that the air from the dischargeend of the piston ywill be permitted to discharge into the atmosphere.

To the stem 59 of the control valves 27 and 55 is attached a ratchet68,.the ratchet 68 of the valve 55 being operatively engaged by a pawl69 operated through a lever 7 0 pivotally attached intermediate its endsat 71 to a portion of the frame 5 and with the end of the lever remotefrom the pawl terminating adjacent the standard 7 for engagement by astop 72 adjustably carried on the standard for actuating the lever uponthe upward movement thereof.

It will be observed from an inspection of Figure l of the drawing thatthe ratchet 68 is of asaw toothed construction whereby to provide for aquarter revolution of the rotor .58 of the valve upon each upwardmovement of the standard 7. i

Accordingly each time the standard is raised the piston 50 in thecylinder 49 is actuated for swinging the arm in either a'forward 1 orreversed direction, as the case may be.

The control valve 45 for controlling the vertical movement of thestandard 7 has the stem of its rotor provided with an'arm 73,illustrated in detail in Figure l() of the drawing, which extendstransversely of the valve-cas- ,ing with its ends protruding at oppositesides thereof.

The Stem 59 of the Valve rotor is inserted in a slotted opening 74 ofthe arm to permit transverse sliding movement of the arm and is urged inone transverse direction by a spring 75 interposed `in theslottedopening between the end thereof and said stem.

As illustrated in Figure l of the drawings, the arm 7 3 extends in agenerally verticaldirection with its upper end disposed in the path ofmovement of the arm 47 of the gear` 6. Accordingly during the movementof the arm 47, the same will engage the upper end ofthe varm 7 3 so asto actuate the valve and moving Nys the rotor thereof one position foradmitting. air to one end of the cylinder 41.

At the ccmpletion of the movement of the arm 47, for effecting aswinging movement of the stacker arm 8 from one of its extreme positionsto the other, the arm 47'rides over the end of the arm 73 and the latterarm is then returned to its original position by a spring 76. Throughthis action the valve is -then returned to its original position foradmitting l the airinto the opposite end of the cylinder 41 whereby toactuate the piston 42 and alternately raise and lower the standard 7.

j In order to regulate the extent of vertical movement of the stackerarm, in accordance withan increase or decrease in the size of the stackof the sheets, an automatic adjusting mechanism is provided Vforlimiting such vertical movement of the stacker arm by actuating thevalve tervals.

This adjusting mechanism comprises a vertically disposed screw 77 havingits upper and lower ends reversedly threaded, as clearly illustrated inFigure 12 of the drawing and, nponthe lower end of which is threaded aat greater or more frequent inblock 78 and with a similar block 79threaded on the upper portion thereof, the blocks'thus being adaptedforopposite vertical movement upon the rotation 'of the screw.

y* Oneendlof' each of the blocks is provided with" a :vertical openingthrough which aguide 80-`is inserted permitting vertical slidingmovement yof the'block onthe guide, the

' guideserving to prevent'rotary movement of y the block during thelrotation of the screw. A trip' 81 is pivotally attached to the upperblock 79 andto-which is attached one end of av cable-82 extendingupwardly over a pulley 83 carried at the lower end of the arm 73 andextending downwardly with its opposite end attached to the lowermostblock 78.

At the upper end of the screw 77 is arranged a ratchet `wheel 84 withwhich a pawl 85 is operatively engaged and slidably mounted in aguide-86 secured to the frame by av 'f I hracket87fand with one endarranged in the path o 'f movement ofthe upper end of the arm 7 8 asclearly illustrated in Figure 10 of the drawings. j

Accordingly upon each movement of the arm 7 3 in a direction toward thepawl, the

ratchet wheel 8.4 associated therewith will be actuated for rotating thescrew 77 and eEeetling anadjustment of the blocks-7 8 and 79 thereon. l

The trip 81 is`disposed in the path of movement of the stop 7 2 andadapted for engagement by said stop upon its downward movement.Accordingly upon each downward movement of the standard 7 the vtrip 81is moved downwardly and through its engagement with the lower end ofthearm 7 3 operates to return said arm to its original position after beingreleased from the arm 47 The cable 82 is always maintained in a tautcondition through the opposite movement of theblocks 78 and 79 upon'thescrew and it will be apparent that as the block 79 isadj usted upwardlyupon the screw the interval of engagement of the trip by the stop 72 1sreduced to effect an earlier return of lthe arm 7 3. The slidingconnection of the arm upon the valve permits a disengagement of the armf from the upper horizontal yswinging arm 47.

A mechanism is also provided for controlling the releasing action of thevacuum cup 15 'through the actuation of the control valve 27 an'dadapted forv adjustment so as to time the releasing action of the cup inaccordance with the adjustment in the extent of vertical movement of thestacker arm. This control valve 27 also has its stem provided with aratchet wheel88, with which a pawl 89 is op- Ieratively engaged andextends vertically of the frame with its upper end formed into a screw90.

A threaded rod 91 isdisposed .parallel with ythe screw 90 with itslowe;A end rigidly secured-to the frame 5. Sprocket wheels 92- allelframe members 99 disposed at opposite sides of the sleeve. v

A ring member 100 is formed at the end ofthe frame members 99 remotefrom the pawl 89 and is disposed horizontally so as to permit the freevertical movement of the standard 7 therethrough. 'l A pair of lugsV101are disposed at .diametrically opposite sides atthe inner peripheryof the ring and on the vare pivotally carried in a pair'of spaced parareadapted for engagement by a pair of projections 10.2 formed atdiametrically opposite sides of astop 103 secured to the standard abovethe-frame 5.

The projections 102 are adapted to pass freely through the ring duringthe vertical movement of the standard 7 when the stacker arm 8 has beenswung in onel direction and are adapted for engagement with the lugs 101of the ring during such vertical move- I ment? when'the stacker arm hasbeen swung p into its operative position.

f Upon the engagement of the lugs '101 by said projections of thestopthe frame composed of the parallel members 99 will be pivotally actuatedthrough its mounting on the rod 99 bythe trunnion'so as to actuate thepawl 89.

A Each movement ofthe pawl 89 serves-to reverse the position of thecontrol valve 27 wherebyto control the engaging or releas- 1n`movement-of the vacuum cup.

the reifersing action of the cylinder control- 'in the vacuum cup inaccordance with the variation in the extent of vertical movement of the"standard, provision is made for vertica'lty adjusting the sprocketwheels 92 whereby toadjust the ring 100 with respect-to the stop 103.

For Athis purpose `a bell crank lever 104 is pivoted upon a bracket 105carried -by the sleeve associated with the sprocket wheel 93 and towhich lever is operatively attached a pawl 106 engageable with a' set ofratchet4 teeth 107 formed on the upperrface of the sprocket wheel 93.

kAna'djust/able stop 109 is carried by one4 of the sleeves`95 torengaging the under side of the pivoted frame 99 whereby to limit thedownward movement of the end of the frame disposed adjacent the'pawl 89.The pawl 89 isalso slidably extended through a guide 110 to insure theengagement thereof with its associated ratchet wheel.

It is to be understood that the stop 103 is positioned upon thestandard7 so that the projections 102 of the stop will engage the lugs 101 ofthe pivoted frame for reversing I the position of the control valve 27only upon each complete forward and backward swinging movement of thestacker arm so that the vacuum cup will be released from the sheet ofmaterial only when the arm has been swung into position upon the sheetswhich are being stacked, or in such a position where 1t is de sired torelease the sheets.

It will be apparent from the foregoing that by initially positioning therotors of the respective valves in the proper manner `with respect tothe compressed air feed pipe eX- tending to t-he opposite ends of theassociated cylinders that the stacker arms will pick up the sheets ofmaterial singly, hoist the same and swing the sheets into apredetermined osition whereupon the sheets arelreleased rom the vacuumcup and the arm is returned to itsoriginal position and lowered forrepeating the operation.

It is obvious that my invention is suscepti ble to various changes andmoditicationsin vconstruction without departing fromv v the spirit ofthe, invention or the scope of the appended claims, and I. accordinglyclaim all suhdforms of the device to which l am en- .r i y.

order to regulate the intervalbetween Having thus described myinvention, what I claim'a's new is:

l. A 'stacker comprising a rotatable standard mounted for verticalsliding movement, a horizontal stacker arm at the upper end of thestandard, -independent fluid pressure operating means for the standardand the arm arranged to reversibly actuate the same in their respectivemovements and automatic control means y,for said operatingmeansproviding for the movement of the standard and the arm in predeterminedtimed relation, and operable through the movement of said standards.

2. A stacker comprising a vertically and horizontally movable stackerarm, independent f luid pressure operating-means for the 'arm arrangedto reciprocally actuate the same in its respective movements andautomatic control means for said operating means providing for thevarious movements of the arm in predetermined timed relation, and

operable through the movement of said arm,

said operating means comprising cylinders having pressurev operatedpistons arranged therein and means operatively connecting the same withthe arm fort-he simultaneous vertical andA horizontal movement thereof.

3. A stacker comprising a rotatable standard mounted for verticalsliding movement, va horizontal' stacker arm at the upperjend of thestandard, work gripping elements carried at the outer end of the arm,means carried by the arm for releasing said gripping means from thework', independent fluid pressure voperating means for the standard, forsaid arm and for said releasing means arranged to actuate the same in apredetermined timed relation and automatic control means for saidoperating means, said control means being operatively associated withthe ment of the arm.

4. A stacker comprising a vertically and `operating means, and operablethrough the movement of the arm, said operating means for said arm andsaid work releasing means comprising cylinders having pressure operatedpistons arranged therein, said arm operating means being operativelyconnected with the arm for the simultaneous vertical and horizontalmovement thereof. j y

5. A-stacke'r comprisi'n a verticallyand horizontally movable stac erarm, work engaging -means carried by said arm, work releasing meanscarried by the arm and. operatively connected the engaging actuating thearm in its respective movement,

automatic control means for said operating'vv means adapted to reversethe operatlon therei operating means loperable -to reverse the operationthereof, means carried by the arm,

means, fluid-pressure operated'm'eans vfor the arm, automatic controlmeans'for sald operable through a predetermined movement thereof foractuating said control means and means for maintaining the work engagingmeans in a parallel position with the stacked Workdurin the movement ofthe arm` 6. A st'ac er comprising'a vertically and horizontally'movablestacker arm, Work engaging means carried by said arm, work releasingmeans carried by the arm and operatively connected With the-engagingmeans, iiuid pressure operating means for the `arm v and said workreleasing means, automatic control means for said operating means and`operable throughV a predetermined vertical movementof the arm and meansfor malntaining the Work engaging means in a parallel position with thestacked work during the movement of the arm, said paralleling meanscomprising a gear operable through the horizontal swinging movement ofthe arm, a gear carried by said work engaging meansand a -lexible shaftcarried by the arm having pinion 4gears at each end operativelyconnected with said first named gears.

` 7. A stacker comprisin'gfa vertically and #so horizontally movablestacker arm, independentv fluid pressureoperating means for .actuatingthe arm in itsrespective movement,- v.automatic control meansf for saidoperatrng" means adapted to` reverse the operation there- .of atpredetermined intervals and automatic means for decreasing the intervalof the reversing movement of the vertical-operating means when the armreaches its predetermined position during its horizontal move-` ment andoperable by each successive vertical movement of the arm. 4

' 9. Al stacker comprising a vertically and horizontally movable stackerarm, ,independent Huid pressure operatingmeans for of at predeterminedintervals, work engaging vacuum cups carried by the arm,' releasingmeans for the cups, automatic control means fr saidf` operating meansand said vacuum cup releasing means, said control means for theoperating-means being adapted to re-V verse the operation thereof atpredetern'iinedy 8. A stiackerlomprising a vertically and-y intervalsand automatic means for decreasing lthe interval of the reversingmovement of the verticaloperating means and inthe operatlon' of saidreleasing means. y .\10. A stacker comprising -a vertically andhorizontally movable stacker farm, inde-l pendent fluid pressurevoperating means Vfor actuating the arm in its respective movement,automatic control means forsaid operating `means adapted to reverse `theoperation thereof at predetermined intervals, work engaging vacuum cupscarried by the arm, releasing means for the cup, automatic control meansfor4 said operating means'and said vacuum cup releasing means, saidvcontrol means for the operating means being adapted to reverse theoperation-thereof atpredeterrnined intervals and independent meansforautomatically decreasing the interval of the reversing movement of theVertical operating means and for the operation ofsaid releasing means. I

11. A stacker comprising a vertically and horizontally movable stackerarm, independent fluid pressure operating means for ac-' tuating the armin its res ective movement,

automatic control means orsaid operating means adapted to reverse theoperation therei of at predetermined intervals, work engaging vacuumcups carried by the arm, releasing means for the cup, automatic controlmeans for said. operating means and said vacuum cup releasing means,said'cont'rol means forv theoperating means being adapted to reverse theoperation thereof at predetermined intervals and independent means forautomatically decreasing the intervalfof the l treversing movement ofthe vertical operating means vand for the operation of said releasinging'operable uniformly by successive vertical movement of the arm whenthe arm reaches a predetermined tal movement. c

12. A stacker comprising a vertically and horizontally movablestackerarm, independent Huid pressure operating means for actuating thearm in its respective movement,

automatic control means for said'operating means, said last namedautomatic means beposition during its'horizonmeans adapted to reversethe operation thereof at predetermined intervals, work engaging vacuumcups carried by the arm, releas.

ing means for the cup, automatic control means for saidnoperating meansand said -vacuum cup releasing means, said control means for theoperating -means being adapted to'reverse the operation thereof atpredetermined intervals and independent means for automaticallydecreasing the interval ofthe reversing movement of the verticaloperating means and for the operatlon of said releasingy means, saidlast named automaticmeans-lize` ing operable uniformly by successive`vertical movement of the arm when the arm reaches a predetermined`position during. -its las horizontal movement, and operating meanscarried by the arm for said last named automatic means and adapted touniformly actuate the same upon the vertical movement of the arm in onedirection.

13. A stacker comprising a vertically and horizontally movable stackerarm, reversible fluid pressure operating means for the arm,

l automatic control means for said operating means adapted to reversethe operation thereof at predetermined intervals, Work engaging vac-uumcups carried by the arm, releasing means for the cups, automatic controlmeans for said operating means and vacuum cup releasing means,independent means for automatically decreasing the intervals inreversing movement of the vertical operating means and for the operationof said releasing means, said automatic control means comprising fluidpressure control valves communieating with the operating means forreversing the movement thereof, actuating means for the valves andoperating means carried by the arm engageable with said valve actuatingmeans and arrangedfor operating the valves-upon a predetermined movementof the arm. l

14. A stacker comprising'a vertically and horizontally movable stackerarm, reversible fluid pressurel operating means for the arm, automaticcontrol means for said operating means adapted to reverse the operationthereof at predetermined intervals, Work engaglv ing vacuum cupscarriedby the arm, releasing'means for the cups, automatic control means forsaid operating means and vacuum cup releasing means, independent meansfor automatically decreasing the intervals in reversing movement of thevertical operating means and for the operation of said releasing means,said automatic control means comprisinguid pressure control valvescommunicating with the operating means for reversing the movementthereof, actuating means for the valve and operating means carried bythe arm engageable with said valve actuating means and arranged' foroperating the valve 'upon a predetermined movement of the arm, andmea-ns connecting the valve actuating means with the automatic reversingand control means for maintaining the same inuniform relative position.

In testimony whereof I affix my signature.

4ENOS L. DONNELLY.

